Rotary pump impeller



Feb. 6, 1934. B s, CARR 1,945,273

ROTARY PUMP IMPELLER Filed Feb. 8, 1932 Patented Feb. 6, 1934 PATENT ol-"Flcr:

ROTARY PUMP ILIPELLEB Bradley S. Carr, Chicago, Ill.,

assignor to American Manganese Steel Company, Chicago, lll.,V l.

corporation Aof Maine Application February 8, 1932. Serial No.

` 2 Claims. (Cl. 103-115) This invention relates in general to centrifugal pumps of the type designed primarily for handling a mixture of liquids and solid substances as in dredging operations and has particular reference to an improved impeller structure for such pumps.

An important object of the invention is to provide an impeller structure for centrifugal pumps of the type described having unusually effective qualities for resisting wear and otherwise accounting for the efiicient operation and economical construction of the pump assembly.

The invention is exemplifled in the combination and arrangement of parts shown in the accompanying drawing and described in the following specification and is more particularly pointed out in the appended claims.

In the accompanying drawing:

Fig. 1 is a view in front elevation of a pump impeller constructed in accordance with the present invention; and,

Fig. 2 is a View in vertical section.

Referring now to the drawing in detail 1 represents the impeller hub which is cast or otherwise formed with an integral back disc 2. 3 represents the front disc having a customary eye or inlet opening 4. The vanes 5 are shrouded by the front and back discs as is customary to complete the impeller structure and in practice the structure is housed in a suitable casing (not shown).

It is accepted practice to cut away or otherwise fashion the inner ends of the vanes 5 to provide a throat 6 for the inow of water with solid matter in suspension and the present invention has to do with the design of the inner ends of the vanes to avoid undue wear on these parts.

As heretofor practiced the ends of the varies have been out with relatively wide curves commencing with the front end of the hub and terminating in linewith the periphery of the eye 4 in the front disc 3. These curvatures present the vane ends at a rather severe angle to the horizontal axis of the open side of the impeller and as the result the incoming material flowing into the impeller parallel with this horizontal axis impinged against the ends of the vanes with such force that the vane ends were frequently damaged. Furthermore the material entering the throat 6 and making a 90 degree turn in response to the centrifugal force developed, wasthrown out radially from the hub with considerable force and impinged the ends of the blades with sufficient impact to injure the same. In other words when the vane ends were cut with a wide sweeping curve rthe distance traversed by the solids in suspension was such that they developed considerable velocity by the time they came in contact with the blade ends.

According to the present invention the inner ends of the vvanes are cut or otherwise fashioned to shorten up, so to speak, the distance traversed radially by the solids in coming in contact with the ends of the vanes. As a result the force of impact against the blade ends is considerably lesscned and the ends are thus protected against undue wear and injury.

The peculiar curvature of the blade ends as contemplated in the present invention also presents a low curve to the inflowing material so that it does not4 strike the blade ends at such an abrupt angle when it flows into the throat 6.

In realizing this objective the inner ends of the vanes are fashioned to approximate the curvesA indicated as at '7. These curves are designed to leave more or less abrupt shoulders as at 8 which are offset inwardly of the periphery of the eye 4 and with the continuations of the blade ends extending substantially parallel with the vertical axis of the eye 4 and offset inwardly therefrom until their curved extremities 9 meet the periphery of the eye.

With the blades fashioned in this manner the force of impact of the solids against the blades is lessened to such an extent that the wear is re.- duced to a minimum without sacrificing operating efficiency or otherwise defeating the economical construction of the pump assembly.

Preferably the discharge ends of the vanes terv minate at l0, with their outer ends about one' half inch short of the perimeter of the front and back discs 2 and 3.

Obviously those skilled in. the art may make various changes in the construction of the device and the specic method described withoutdeparting from the spirit and scope of the invention as defined by the appended claims, and I therefor do not wish to be limited tothe precise construction. contained herein.

I claim:

1. An impeller for centrifugalpumps for handling a mixture of liquids and solid particles, said impeller having a hub, a throat presented in the direction of the axis of the hub, front and back discs, said front disc having an intake opening presented co-axially of the throat and a vane having the margin of its inner end diverging continuously from and at a relatively low angle to the axis of the hub `and terminating in a shoulder adjacent the intake opening in the front disc,

l l NNW l WH said shoulder having a face perpendicular to the hub axis and extending substantially from the edge of said intake opening to the said continuously diverging margin portion whereby the distance the solid particles must travel in reaching the vanes is reduced thereby preventing the particles from gathering extreme speed before striking the varies. Y

2. An impeller for centrifugal pumps :for handling a mixture of liquids and solid particles,

said impeller having a hub, a throat presented' in the direction of the axis of the hub, front and back discs, said front disc having an intake opening presented co-axlally of the throat and a. vane BRADLEY S. CARR.

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